Yellow Hemerocallis ‘Happy Returns’ and the yellow-orange Coreopsis brightens the purple spikes of Salvia and low mound of lavender blue Nepeta ‘6 Hills Giant’. A quick look at the color wheel illustrates the dynamic duo as ‘complements’. In the language of color, complementary colors intensify each other like a passionate affair. Yellow reads more yellow in purple ‘s presence and purple glows when coupled with yellow. However, align purple solely with green and it becomes somber and melancholy. And lacking the contrasting quality of its complement, you may not even be able to see it. Couple that with an overcast sky and driving rain, and you get an unappealing greeting for an entry garden. Add yellow and its merging adjacent yellow-orange to transform purple and green into an elegant expression of vibrant contrasting forms that emotionally adds a cheery welcome.